I’ve seen a few videos that utilize iClone and its integration with LiveLink to feed animations into MetaHumans. iClone isn’t cheap, but it has the advantage that it has a library of animations you can choose from, including idle animations.
Exciting stuff, though there are some bumps along the way trying to get iClone to read in the skeleton exported from UE4 as a result of what seems like an FBX export bug in UE.
Check out these videos, though: